Conventionally, backup power supplies are provided to address an electric power failure (blackout) in emergencies such as disasters in communication base stations, communication equipment such as data centers, hospitals, broadcast stations, etc. Among the backup power supplies, as a backup power supply using the fuel cell, there is known a configuration in which a fuel cell generates electric power using hydrogen stored in a hydrogen tank (see Patent Literature 1). The backup power supply having this configuration has an advantage that the fuel cell can be started-up (activated) quickly. However, when all of hydrogen inside of the hydrogen tank has been consumed, the hydrogen tank must be replaced. A work for replacing the hydrogen tank is burdensome and cost of the replacement of the hydrogen tank is needed. If catastrophe such as an earthquake, a typhoon, or a hurricane happens, a traffic network such as a road is cut, and the hydrogen tank will not be supplied. In this case, there is a possibility that the backup power supply does not work in the disasters in which backup power supplies are especially needed.
By comparison, there is a known a configuration in which the hydrogen tank is not used as the power supply using the fuel cell. As a typical fuel cell of this, there is a power supply which uses a fuel of a hydrocarbon based gas supplied by a gas utility (infrastructure of gas supply) according to a demand. In this fuel cell, typically, a reformer reforms the fuel of the hydrocarbon based gas to generate a reformed gas containing hydrogen as a major component, and the reformed gas is supplied to a fuel cell stack, which generates electric power (e.g., see Patent Literature 2).
An example of the fuel cell system having the above configuration will be specifically described. As shown in FIG. 10, in a fuel cell system 110, a fuel is supplied from a raw material supply line 101 to a reformer R0 via a desulfurization device D0 and a raw material supply device Bt by opening a raw material shut-off valve Va0. The reformer R0 reforms the fuel into a reformed gas containing hydrogen as a major component, and the reformed gas is supplied to a fuel cell stack F0 via a reformed gas supply line 102. After passing through the fuel cell stack F0, the reformed gas (off-gas) is supplied to a heat supply device B0 via an off-gas line 103 and a combustion gas valve Vb0. The heat supply device B0 combusts the off-gas to warm-up the reformer R0.
An oxidizing gas supply device S0 supplies air to the fuel cell stack F0 via an oxidizing gas supply line 104. The fuel cell stack F0 carries out power generation by causing the reformed gas and the air to be reacted with each other. Reference numeral 105 designates a reformed gas reuse line 105 for supplying hydrogen to the desulfurization device D0 including a hydrogenated desulfurization device. Reference symbol Vc0 designates a reformed gas reuse valve Vc0.